Diamond not only represents eternity, but also is an important material in integrated quantum photonic devices

The emergence of integrated quantum photonics makes it possible to generate, manipulate and detect quantum states of light in micro waveguide circuits. Implementing these three operations simultaneously in a single independent integrated platform is a key step to realize quantum photon technology. Diamond has gradually become a particularly promising material because it can simultaneously take into account the large light transmission (transparency) range required for manufacturing low loss optical quantum circuits and the optical active defects required for achieving efficient single photon emission. In addition, the high Young's modulus of diamond makes it an ideal choice for tunable optical mechanical devices to realize active quantum state operation.

The research group of Professor Wolfram H. P. Pernice of the University of Munster, Germany, published an overview paper in the journal Advanced Quantum Technologies, and reported the latest progress in realizing integrated quantum photonic devices based on diamond, including single photon emitters, passive and active tunable waveguide circuits, and integrated superconducting single photon detectors. In the review, the author also proposed the challenges of realizing fully integrated quantum photonic circuits based on diamond in the future, such as the technical difficulties in pump light filtering when optically pumping color centers, the problem of photon homogeneity (indiscernibility) when multiple single photon emitters are coupled with the same integrated waveguide network, and how to improve the performance of single photon detectors by special polishing of diamond films. (Reprinted on China Superhard Materials Network)